AB0841 Analysis of the functional state of hip joints (HJ) before total hip arthroplasty (THA) in patients with ankylosing spondylitis (AS): data of a retrospective analysis

Abstract

BackgroundInjury of hip joint (HJ) in patients (pts) with ankylosing spondylitis (AS) is considered as a factor of unfavorable prognosis, which can lead to rapid disability of pts.ObjectivesTo assess the functional state of HJ before performing THA in patients with AS.MethodsThis retrospective study included 170 pts with a verified diagnosis of AS, who met the modified New York criteria of 1984, who were treated in the traumatological and orthopedic department in the period from 1998 to 2020, THA was routinely performed to all pts. Most of the pts were male (80.6%). 64% of them did not work due to the disease. Functional insufficiency of the joints at the time of surgical treatment in 64.1% of all the cases corresponded to III grade, in 26.5% - to IV grade, in 9.4% - to II grade. 82.9% of pts had low activity of the disease according to the BASDAI index at the time of surgical treatment and 17.1% of them had high activity. 53 (31.1%) pts were receiving bDMARDs and 87% of them were TNF-alpha inhibitors. The Harris quantitative scale was used to assess the functional state of HJ.Results:ParameterAll patients (n=170)bDMARDs (+) n=53bDMARDs (-) n=117Age, years, Me±δ38,1±11,337,5±12,338,3±10,8Age of AS debut, years, Me± δ20,7±8,421,2±8,420,5±8,4Age at the time of diagnosis, years, Me± δ27,6±9,127,6±9,927,6±8,9Average delay in diagnosis, years, Me± δ6,8±5,86,4±4,37,1±6,4Average duration of the disease, years, Me± δ17,0±8,516,2±8,017,5±8,7Average duration of pain in HJ, years, Me± δ7,4±4,86,1±2,2*8,0±5,4Average level of pain in HJ, VAS, Me± δ72,3±14,069,9±12,973,4±14,5Average overall score on the Harris scale before surgery38,0±15,442,1±15,036,1±15,3*The average level of pain on the Harris scale, VAS,, Me± δ15,6±8,417,5±8,314,7±5,5Antalgic Gait (absent/mild/moderate/severe), %42,9/42,9/11,8/2,441,5/35,8/18,9/3,843,6/46,2/8,5/1,7Walking a distance (unlimited /1500 meters /500 meters/in the apartment/unable to walk), %2,4/21,2/0,6/44,7/27,1/4,12,4/21,7/44,7/27,1/4,13,4/21,6/45,2/26,4/3,4Additional support (missing/walking stick for long distances/walking stick permanently/one crutch/two walking sticks/two crutches), %30,6/5,3/4,1/29,5/4,1/26,422,6/7,5/3,8/24,5/7,5/34,034,2/4,3/4,3/31,6/2,6/23,0Putting on shoes (without difficulty/ with difficulty/ impossible)4,2/65,8/30,07,4/67,9/24,53,4/64,9/33,3Fixed adduction (<10°/>10°), %30,0/70,026,4/73,631,6/68,4Fixed internal rotation (<10°/>10°)22,9/77,126,4/73,621,4/78,6Flexion contracture (<15°/>15°), %39,4/60,641,5/58,538,5/61,5*p<0,05ConclusionThe vast majority of pts with AS had pronounced severe disorders of HJ before THA - the average score on the Harris scale was 38.0±15.4. Most of the patients (85.9%) had severe and moderate lameness, with the need for additional support in 69.4% of cases. Objective signs of functional disorders (fixed inward rotation and reduction, flexion contracture) of HJ were detected in more than half of the cases. According to the assessment of most parameters of the Harris scale, there were no significant differences between pts with AS on bDMARDs and without bDMARDs, except for the average duration of pain in HJ and the overall value of the scale (6.1±2.2 vs 8.0±5.4 and 42 vs 36, respectively, p<0.05 in both cases).Disclosure of InterestsNone declared